Risk factors for Alzheimer’s dementia may emerge as early as the teen and young adult years, particularly in African Americans, according to new research reported at the Alzheimer’s Association International Conference (AAIC) 2020.
These risk factors include heart health factors such as high blood pressure, high cholesterol and diabetes, as well as social factors like education quality. According to the Alzheimer’s Association, older African Americans are about twice as likely to have Alzheimer’s or other dementias compared to whites.
“By identifying, verifying, and acting to counter those Alzheimer’s risk factors that we can change, we may reduce new cases and eventually the total number of people with Alzheimer’s and other dementia,” said Maria C. Carrillo, Ph.D., Alzheimer’s Association chief science officer. “Research like this is important in addressing health inequities and providing resources that could make a positive impact on a person’s life.”
“These new reports from AAIC 2020 show that it’s never too early, or too late, to take action to protect your memory and thinking abilities,” Carrillo said.
The Alzheimer’s Association is leading the U.S. Study to Protect Brain Health Through Lifestyle Intervention to Reduce Risk (U.S. POINTER), a two-year clinical trial to determine whether lifestyle interventions that simultaneously target many risk factors protect cognitive function in older adults who are at increased risk for cognitive decline.
In a population of more than 714 African Americans in the Study of Healthy Aging in African Americans (STAR), Kristen George, Ph.D., MPH, of the University of California, Davis, and colleagues found that high blood pressure and diabetes, or a combination of multiple heart health-related factors, are common in adolescence and are linked to poorer late-life cognition.
The study involved 165 adolescents (ages 12-20), 439 young adults (ages 21-34) and 110 adults (ages 35-56). Mean age at cognitive assessment was 68.
The researchers measured participants’ cognition with tests of memory and executive function. The results show that having diabetes, high blood pressure, or two or more heart health risk factors in adolescence, young adulthood, or mid-life was associated with statistically significantly worse late-life cognition. These differences persisted after accounting for age, gender, years since risk factors were measured, and education.
Before this study, it was still unclear whether cardiovascular disease (CVD) risk factors developed prior to mid-life were associated with late-life cognition. This would have significant implications for African Americans who are known to have higher CVD risk factors compared to other racial/ethnic groups from adolescence through adulthood.
The findings suggest that CVD risk factors as early as adolescence influence late-life brain health in African Americans. Efforts to promote heart and brain healthy lifestyles must not only include middle-aged adults, but also younger adults and adolescents who may be particularly susceptible to the negative impact of poor vascular health on the brain.
In what the authors say is the first study to report on the issue, higher early adulthood (age 20-49) body mass index (BMI) was associated with higher late-life dementia risk.
Relatively little is known about the role of early life BMI on the risk of Alzheimer’s and other dementias. The researchers looked at a total of 5,104 older adults from two studies, including 2,909 from the Cardiovascular Health Study (CHS) and 2,195 from the Health, Aging and Body Composition study (Health ABC).
Of the total sample, 18% were Black and 56% were women. For women, dementia risk increased with higher early adulthood BMI. Compared to women with normal BMI in early adulthood, dementia risk was 1.8 times higher among those who were overweight, and 2.5 times higher among those who were obese. Analyses were adjusted for midlife and late life BMI.
The researchers found no association between midlife BMI and dementia risk among women.
For men, dementia risk was 2.5 times higher among those who were obese in early adulthood, 1.5 times higher among those who were overweight in mid-life and 2.0 times higher among those who were obese in mid-life, in models also adjusted for late life BMI. For both women and men, dementia risk decreased with higher late life BMI.
Source: Alzheimer’s Association